In Patent Document 1, there is described a staircase wave generating circuit. The circuit described in this document includes a voltage-dividing circuit, a switch circuit, and a trigger circuit. The voltage-dividing circuit has a plurality of resistors which are connected in series between two electric power sources which are different in voltage level from each other, and divides a difference in potential between the two power sources into a plurality of levels. The switch circuit has a plurality of switch elements (FETs) which are connected in series between the two power sources, and the plurality of switch elements are respectively connected in parallel to the plurality of respective resistors. One end of the switch circuit is a signal output terminal, and the trigger circuit turns on the plurality of switch elements sequentially from the side of the signal output terminal. Thereby, voltage levels which are resistance voltage divided are output as a stair-shaped voltage (staircase wave) from the signal output terminal.
In Patent Document 2, there is described a staircase wave generating circuit. The circuit described in this document includes a generator that generates digital data containing a staircase wave, a digital-analog converter that converts the digital data into an analog current, a circuit that shifts a level of the analog current, a current-voltage converter circuit that converts the analog current into a voltage output, and a transistor that differentially-amplifies the voltage output.